Andy Warhol has become such an icon that a photo of his medicine cabinet is expected to fetch at least $6,000 on April 10 at Sotheby’s.

The photo — and another showing Warhol’s wig, glasses and Longines watch — was taken by David Gamble, who spent eight days shooting in Warhol’s East 66th Street townhouse in 1987 before it was sold.

Gamble was given access to Warhol’s lair by the artist’s executor, Fred Hughes, who hoped Gamble’s photos, featured in the Observer in London, would boost prices at an upcoming auction of Warhol’s estate, which turned out to be a huge success.

The Brit, a rock drummer before turning to photography, told me from his home in New Orleans that it was difficult to capture a ghost.

He was happily surprised to find no one had emptied the shelves stuffed with cosmetics and medicines.

“You can’t get more voyeuristic than a medicine cabinet,” Gamble said.